1. Technical Field
The present invention relates to an active matrix liquid crystal display (LCD) device and a manufacturing process for the same and in particular, relates to an active matrix liquid crystal display device with a light-shielding structure formed by laminating color layers instead of a black matrix and a manufacturing process for the same.
2. Background Art
In recent years, it is strongly required that an active matrix LCD device with a high display quality can be obtained at smaller cost.
In a related LCD device, in order to shield a light entered from a frame part, a light shielding layer called a black matrix (BM) is formed on a substrate having a color filter (color filter substrate). This black matrix consists of a metal such as a chrome (chrome oxide) or a resin or the like. However, in order to decrease manufacturing costs, a technology for omitting the black matrix is proposed. For example, an LCD device which has a light shielding layer on a frame part surrounding a display area is disclosed in Japanese Patent Application Laid-Open No. 2000-29014 and Japanese Patent Application Laid-Open No. 2003-14917. The light shielding layer is formed by laminating colored layers which consist of at least two colors out of the plural colors.
FIG. 5 shows an outside plan view of a panel in a related common LCD device. FIG. 6 is a cross-sectional view along the VI-VI line in FIG. 5 and shows a structure of the LCD device having a black matrix. On the other hand, FIG. 7 shows the structure of a color filter substrate of the related LCD device where the black matrix is omitted, and FIG. 7 is also a cross-sectional view along the VI-VI line in FIG. 5.
As shown in FIG. 5, the related LCD device includes a display area 1 where a pixel is formed and a frame part 2 which surrounds the display area 1. As shown in FIG. 6, in order to hide wirings which are formed on an array substrate 30A and are drawn out from the display area 1, a black matrix 25 is formed on the frame part 2 of a color filter substrate 20A in which a color filter is formed. In this structure, the frame part 2 around the display area 1 is shielded from a light by the black matrix 25. Therefore, even though an electric field is applied between the wirings, deterioration of the display quality in the frame part 2 because of the light transmitted through this part does not arise.
On the other hand, as shown in FIG. 7, a color filter substrate 20B is not provided with a black matrix, but a light shielding structure is formed by laminating two or more colored layers. That is, the frame part 2 is shielded from a light by laminated structure composed of the same colored layers as those of the display area 1 (for example, red (R) colored layer 21, green (G) colored layer 22, and blue (B) colored layer 23).